Family members say a 30-year-old Navy man was among those killed in the crash of a military helicopter in southern Afghanistan. Kelly Lockman said Wednesday that her brother, David Blake McLendon, was one of the servicemen killed in the crash Tuesday morning in the Daychopan district of Zabul province.

The U.S. military has not disclosed the helicopter's mission, and the cause of the crash is not clear.

"On behalf of the entire Naval Special Warfare community -- we extend our sincerest condolences to all the families of our fallen brothers, our Navy SEALs and support tech, Army air crewmen, and coalition personnel," said Rear Adm. Edward Winters, commander, Naval Special Warfare Command. "Our prayers are with these families during this very difficult time."

McLendon was a Navy cryptologic technician assigned to an east coast Naval Special Warfare unit. He entered the Navy in 1998 and was a graduate of Thomas County Central High School in Georgia. During his 12-year Navy career, McLendon served at various Navy commands in Norfolk, Pearl Harbor, and Brunswick, Maine. His fellow service members said they remember McLendon as a consummate Navy professional.

"These men bravely and unselfishly answered the nation's call to defend freedom and protect the nation and its allies from terrorism," said Rear Adm. Winters. "The loss of these brave warriors will only strengthen our resolve in the fight against extremism and terror."

Lockman said her brother, a 1998 graduate of Thomas County Central High School, was a senior chief in Naval Special Warfare stationed in Little Creek. She says he trained with a Navy SEAL team but was not serving as a SEAL.

She says a military chaplain informed the family of McLendon's death on Tuesday.

"He loved to go fishing," Lockman said of her brother, who went by his middle name.

She said that when he came home in June, he went fishing with family and friends and went to Turner Field in Atlanta to see a Braves game. "It was the first time he'd been there," she said.

The body was to arrive Wednesday at Dover Air Force Base in Delaware, family members said.

Brian Bass, a close friend, said there was never a dull moment when McLendon was around. “He was just a joy to be around, the funniest guy ever, guaranteed to put a smile on your face,” Bass said.

McLendon’s former sister-in-law, Meredith Harper, said McLendon loved children and his family. “He loved what he did,” Harper said.

Late Tuesday afternoon, she had not told her son, Harper McLendon, about his uncle’s death. She knows she must. “He looked up to Blake and everything he did and adored Blake,” Harper said.

McLendon, 30, had deployed previously to the Middle East, but hadn’t been in Afghanistan long this time, Lockman said. He arrived less than a month ago.McLendon, who went by Blake, was a 1998 graduate of Thomas County Central High School. He entered the Navy after graduation, following in the footsteps of his father and grandfather. He was a cryptologic technician who worked with SEAL teams and was stationed at Joint Expeditionary Base Little Creek.